If the U. S. produces 1 unit of gas in 20 hours, and 1 unit of toys in 16 hours, how many toys must the U. S. give up to produce one unit of gas?

What we know:

1 unit gas=20 hours

1 unit toy=16 hour

If we were to give up producing 1 unit of toy (and have 16 hours free up), that still wouldn't be enough to produce 1 unit of gas. We still would need 4 additional hours to produce 1 unit of gas. 4 hours represents a fourth (1/4) of the time needed to produce 1 unit of toy. Thus, 4 hours represent 1/4 or 0.25 of a toy. In total, 1.25 toys would need to be sacrificed in order to produce a unit of gas. Since there is no such thing as a quarter (1/4 or 0.25) toy, we need to round 1.25 to a whole number (in this case 1.25 is rounded to 1). 1.25 toys is the technically correct answer, but 1 toy is the practically correct one.